The Swainson's Thrush is one of those birds that winters all the way down in South America, and then migrates all the way up to Canada and Alaska in the spring and summer to breed. There are Eastern and Western varieties that part ways somewhere around Mexico. In the East, the bird frequents dense forests and woodlands, but in the West it is more often seen on the streams along the coast. In California, populations have dropped significantly in recent years, which makes this bird one of several that Audubon is hoping to help through habitat restoration. This is another bird named after the English naturalist William Swainson. We're going to deviate for our norm, and show you eBird maps of the entire country, so you can get an idea of the bird's northward push during April (photo by Peter LaTourrette).

Below, we look at the map from the end of March. You can just see the Swainson's Thrush staring to appear in northern Mexico:

But then now, almost through April, look what's going on: